The present invention relates to a method for removing a coating from a portion of optical fiber. In particular, the invention relates to a method for removing an acrylate coating layer from a portion of optical fiber so as to allow splicing, manufacturing of fused-fiber couplers, and writing of Bragg gratings.
As known, optical fibers are largely used in the field of telecommunications for transmitting signals. They essentially comprise an inner cylindrical region, called core, in which the signal is transmitted, and an outer annular region, called cladding, having a lower index of refraction with respect to that of the inner region so as to confine the transmitted signal within the core. Both the above-mentioned regions are usually made of a glass material.
Due to the very small dimensions (typically, 125 xcexcm) and to the fragile material (glass) of which they are made, optical fibers are intrinsically subject to breaking. For the purpose of ensuring a high mechanical reliability in operation, during the drawing process the fibers are coated with a soft material consisting basically of polymers (typically, acrylate), which has the function of protecting the fiber during handling and from atmospheric agents.
In special applications, such as for example for splicing, manufacturing of fused-fiber couplers, or writing of Bragg grating, the acrylate coating must be removed from the fiber so as to uncover the glass region.
Different methods for removing the acrylate coating from an optical fiber are known; they can be essentially classified into two categories: methods with chemical removal and methods with mechanical removal.
Generally, the methods with mechanical removal provide for the use of mechanical tools or devices that are manually operated by the operator to remove the acrylate layer from the optical fiber. Many kind of tools and devices have been proposed in the past for this purpose.
The present invention includes a method for removing a coating from a portion of optical fiber. The method includes the steps of mechanically removing the coating from a first fiber portion, the first fiber portion separating a second fiber portion from a third fiber portion; and chemically removing the coating from the second fiber portion. The step of chemically removing the coating includes immersing the second fiber portion into a liquid solvent, and holding the first fiber portion partially out from the liquid solvent, so as to prevent the liquid solvent from reaching the third fiber portion.